Lennon, who had coins and cups of liquid thrown at him, left shortly after the Dons scored their third goal in the 62nd minute.
Lennon told reporters: "It was very disappointing, uncomfortable if you want to use the word.
"I think it was drink-fuelled. It was a great atmosphere and I don't want to take anything away from Aberdeen's day, it was a great day for them.
"About 30 minutes into the game a coin whistled past my head and actually hit a gentleman in front of me on his back, and he's an Aberdeen fan!"
Lennon has been the victim of a number of crimes during his time at Celtic, the most serious of which saw two men jailed for five years for sending him parcel bombs.